S-91870A749 1/4"-20 x 1/2" ASME B18.3 Tamper-Resistant Torx Plus Stainless Steel Flat Head Screws
Tamper-Resistant Torx Plus Stainless Steel Flat Head Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Enhanced tamper resistance with Torx Plus IPR27 drive prevents unauthorized removal in high-security applications
- Superior corrosion resistance through 18-8 stainless steel construction and passivated surface treatment
- Reliable fastening performance with 70,000 psi tensile strength and Rockwell B70 hardness
- Optimized flush mounting featuring undercut flat head design for seamless surface integration
- Precision thread engagement with Class 2A UNC coarse threads ensuring consistent installation
- Full threading capability provides maximum grip length across the entire 1/2" shank
- Regulatory compliance assurance meeting ASME B18.3 standards and environmental regulations
Professional Applications & Engineering Value
These 1/4"-20 UNC flat head screws deliver critical security and durability for demanding industrial environments. The tamper-resistant Torx Plus drive system provides enhanced protection against unauthorized access in public infrastructure, transportation, and secured facilities. Manufactured from 18-8 stainless steel with passivated finish, these fasteners resist corrosion in harsh conditions while maintaining structural integrity. The undercut flat head profile ensures flush mounting without protrusion, ideal for applications where smooth surfaces are essential. With coarse threading and Class 2A fit, installation is streamlined while maintaining vibration resistance in machinery, electronic enclosures, and outdoor equipment where environmental exposure is a concern.
Specification Summary & Compliance
These security screws feature precision 1/4"-20 UNC coarse threads with Class 2A thread fit tolerances and full threading along the 1/2" length. Manufacturing complies with ASME B18.3 specifications for dimensional accuracy and performance standards. The products are RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting current environmental regulations for hazardous substance restrictions. The 82° countersink angle matches standard tooling requirements for consistent installation across industrial applications.
